Motor monitoring device

Abstract

A motor monitoring device according to one embodiment of the present disclosure is provided with: a rotational speed acquisition unit that acquires rotational speeds of a plurality of motors; an output value acquisition unit that acquires output values of the plurality of motors; a deviation amount calculation unit that calculates a deviation amount between the rotational speed and the output value between the motors; and a graph display unit that plots a plurality of marks indicating a combination of the rotational speed and the output value for each of the motors in a graph region in which one axis is set as the rotational speed and the other axis is set as the output value, the graph display unit including: a graph region setting unit that sets the rotational speed and the output value in the graph region; a display unit that divides the graph region into a plurality of load regions having different load levels on the basis of a plurality of rated times of the motor with respect to a combination of the rotational speed and the assumed output value, and that displays the plurality of load regions in a recognizable manner; a plotting unit that plots the plurality of marks in the chart area; and a connecting line drawing unit that draws connecting lines that connect the corresponding marks in different forms in accordance with the amount of deviation.

Description

Technical Field

[0001] The invention relates to a motor monitoring device. Background Art

[0002] In motors such as spindle motors for machine tools, where the load may vary greatly, there is a risk of heat accumulation and overheating if the heavy load continues. For such motors, various rated times can be set so that they can operate without overheating under specific conditions. As rated times, for example, JIS-C4034-1 specifies a continuous rating that allows continuous operation, a short-time rating that allows operation for a certain time (load time) from room temperature, and an intermittent rating (Japanese: repeated rating) that allows operation for a certain time (load time rate) within a specified cycle time.

[0003] For example, assume the following situation: in a machine tool, the actual operation state of the motor is grasped, and the setting value of the motor speed, etc. is adjusted to reduce the margin for overheating so that machining can be performed more efficiently. As a means for grasping the current operation state of the motor, a load meter is known that sets one axis as the rotation speed and the other axis as the output, and plots the current values ​​of the motor rotation speed and output on a graph showing lines representing the above-mentioned various ratings (for example, refer to Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 10-90011 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] For example, there are devices such as multi-axis machine tools that drive a plurality of motors under the same conditions. In such devices, if the states of the plurality of motors cannot be grasped, there is a risk that the setting values ​​cannot be adjusted appropriately.

[0009] Solutions for solving problems

[0010] A motor monitoring device according to one embodiment of the present disclosure comprises: a rotation speed acquisition unit that acquires the rotation speeds of a plurality of motors; an output value acquisition unit that acquires the output values ​​of the plurality of motors; a deviation calculation unit that calculates the deviations between the rotation speeds and the output values ​​of the motors; and a graph display unit that plots a plurality of marks representing the combination of the rotation speed and the output value for each of the motors in a graph area in which one axis is set to the rotation speed and the other axis is set to the output value, wherein the graph display unit comprises: a graph area setting unit that divides the graph area into a plurality of load areas with different load levels based on a plurality of rated times of the motors for an assumed combination of the rotation speed and the output value, and displays the plurality of load areas in an identifiable manner; a plotting unit that plots the plurality of marks in the graph area; and a connecting line drawing unit that draws connecting lines connecting the corresponding marks in different forms according to the deviations.

[0011] Effects of the Invention

[0012] According to the present disclosure, the states of a plurality of motors can be easily grasped. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a block diagram showing the configuration of a machine tool including a motor monitoring device according to a first embodiment of the present disclosure.

[0014] Figure 2 is exemplified by Figure 1 Figure 2 shows the display of the motor monitoring device. DETAILED DESCRIPTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Figure 1 1 is a block diagram showing the configuration of a machine tool 1 including a motor monitoring device according to a first embodiment of the present disclosure.

[0016] The machine tool 1 includes a numerical control device 10 which is an embodiment of the motor monitoring device involved in the present invention, multiple spindle motors 20, multiple speed detectors 21 for detecting the speed of the spindle motors 20, multiple current detectors 22 for detecting the current of the spindle motors 20, a display device 30 for displaying a screen according to the numerical control device 10, and an input device 40 for a user to input to the numerical control device 10.

[0017] The numerical controller 10 has a memory, a processor (CPU), an input / output interface, etc., and can be implemented by one or more computer devices that execute an appropriate control program. The components of the numerical controller 10 described below are obtained by classifying the functions (processor operations) of the numerical controller 10, and may be components that cannot be clearly distinguished in physical structure and program structure.

[0018] The spindle motor 20 is typically provided as a motor for rotationally driving a cutting tool or a workpiece, and the load of the spindle motor 20 can vary according to the machining conditions regardless of the rotation speed. The rotation speed detector 21 and the current detector 22 can be respectively constituted by known sensors.

[0019] The display device 30 is a well-known display that displays according to the signal input from the numerical controller 10. The display device 30 may be configured integrally with the numerical controller 10. The input device 40 is a device for the user to input information to the numerical controller 10, and can be a well-known structure such as a keyboard and a mouse. The input device 40 may be configured integrally with the numerical controller 10. In addition, the input device 40 may be configured integrally with the display device 30. Specifically, the display device 30 and the input device 40 may be a single input / output device such as a touch panel.

[0020] In this embodiment, the numerical control device 10 includes: a program storage unit 11; a motor control unit 12 that controls the operation of a motor that drives a drive shaft of the machine tool 1 including a spindle motor 20; and a motor monitoring unit 13 that performs the function of the motor monitoring device involved in the present disclosure.

[0021] The program storage unit 11 stores a machining program executed in the machine tool 1. The machining program includes a plurality of blocks for respectively specifying unit actions of the machine tool 1. Each block includes one or more words each consisting of a combination of a plurality of characters. Generally, each block is initially assigned a serial number for identifying the block.

[0022] The motor control unit 12 controls the spindle motor 20 and other drive axis motors of the machine tool 1 according to the machining program, thereby executing the machining process described in the machining program. The structure of the motor control unit 12 is the same as that of a known numerical control device, so detailed description is omitted.

[0023] The motor monitoring unit 13 includes a rotation speed acquisition unit 131 , an output value acquisition unit 132 , a deviation amount calculation unit 133 , a graph display unit 134 , a notification unit 135 , a stop instruction unit 136 , and an override instruction unit 137 .

[0024] The rotation speed acquisition unit 131 acquires the rotation speed of the spindle motor 20 from the rotation speed detector 21. The rotation speed acquisition unit 131 may acquire the rotation speed of the spindle motor 20 via the motor control unit 12.

[0025] The output value acquisition unit 132 acquires output values ​​of the spindle motor 20, such as the current value, power value, and torque value. In the present embodiment, the output value acquisition unit 132 acquires the current value of the spindle motor 20 from the current detector 22, and uses the power value and torque value calculated based on the current value as the output value. However, the output value acquisition unit 132 may be configured to directly use the detection value such as the current value as the output value. The output value acquisition unit 132 may also acquire the output value or the value required to calculate the output value from the motor control unit 12. In addition, the types of output values ​​acquired by the output value acquisition unit 132 may be one type or three or more types.

[0026] The deviation amount calculation unit 133 calculates the deviation amount between the rotation speed and the output value of the spindle motor 20. The deviation amount may be calculated as deviations of the rotation speed and the output value independently, or may be calculated as deviations of values ​​obtained as functions of the rotation speed and the output value.

[0027] The graph display unit 134 plots a plurality of marks indicating combinations of rotation speeds and output values ​​for each spindle motor 20 in a graph area in which one axis is set as a rotation speed and the other axis is set as an output value. The graph display unit 134 includes a graph area setting unit 1341, a plotting unit 1342, a connecting line drawing unit 1343, a reference setting unit 1344, and a reference selecting unit 1345.

[0028] The graph area setting unit 1341 displays a graph area in which one axis is set to a rotation speed and the other axis is set to an output value on the display device 30. The graph area setting unit 1341 divides the graph area into a plurality of load areas and displays the plurality of load areas in a recognizable manner. More specifically, the graph area setting unit 1341 divides the graph area into a plurality of load areas with different load levels based on a plurality of rated times of the spindle motor 20 for an assumed combination of the rotation speed and the output value. Thus, the user can easily grasp the safety or danger level of the operating state of the spindle motor 20.

[0029] The graph area setting unit 1341 preferably displays the plurality of load areas in a manner that can be identified by color or pattern. By adding color or pattern, it is easy to understand which load area the combination of rotation speed and output value belongs to. In addition, by using a color or pattern that can easily intuitively understand the high or low load level of the load area, such as blue, yellow, and red, it is easy to understand the dangerousness of the operating state of the spindle motor 20.

[0030] If the combination of the rotation speed and output value of the spindle motor 20 is set below the continuous rating, the operation of the spindle motor 20 can be continued without limitation on the load of the spindle motor 20. Therefore, it is preferable to set the upper limit of the load range with the lowest load level to the curve representing the continuous rating.

[0031] Preferably, the graph area setting unit 1341 sets the boundary of any load area among the plurality of load areas, preferably the lower limit of the load area with the highest load level, to a line connecting the maximum values ​​of a plurality of rated times (e.g., short-time ratings and intermittent ratings with different load time rates) at the same speed. The combination of the speed and the output value plotted in the area crossing the boundary line means a dangerous output state that may cause a failure immediately. On the contrary, if the boundary line is not crossed, a problem may not occur in a short time.

[0032] The chart area setting unit 1341 may also be configured to select the boundary of at least one of the multiple load areas according to the user's input. Specifically, it may be configured to select the boundary of the load area from the above-mentioned continuous rating, the maximum value of multiple rated times, multiple short-time ratings with different load times, and multiple intermittent ratings with different load time rates. In this way, a load area that is considered appropriate can be set in consideration of the content of the processing to be performed in the machine tool 1, so that the criticality of the spindle motor 20 can be more appropriately grasped.

[0033] The plotting unit 1342 plots a plurality of marks corresponding to the spindle motors 20 in the chart area. The plotting unit 1342 preferably plots the marks in different forms for each corresponding spindle motor 20. As an example, the plotting unit 1342 can plot the marks in a form that can identify the corresponding spindle motor 20 based on differences in the marks, such as shape, color, pattern, etc. Figure 2 In the example shown, which one of the three systems of spindle motors 20 is identified is determined based on the shape of the mark.

[0034] In addition, the plotting unit 1342 may change the shape of the mark according to the state value of each spindle motor 20, such as the load level, temperature, estimated time until the overheating temperature is reached, and the like. Figure 2 In the example shown, a marked pattern (hatched lines) indicates the corresponding load level of the spindle motor 20. As described above, the plotting unit 1342 indicates the status value in a marked form, so that the user can understand the operating status of the spindle motor 20 in various aspects.

[0035] The connecting line drawing unit 1343 draws the connecting lines connecting the corresponding marks in different forms according to the deviation amount in the plotting area. Specifically, the connecting line drawing unit 1343 can draw the connecting lines in different forms according to whether the deviation amount exceeds the specified deviation allowance, or can draw the connecting lines in different forms according to the ratio of the deviation amount to the specified deviation allowance. For example, it is considered to use color, thickness, pattern, etc. as the form of the connecting line that changes according to the deviation amount, so that the user can understand the size of the deviation amount. As a result, the user can easily understand the motor whose load state is greatly different from the load state of other motors 20.

[0036] The connecting line drawing unit 1343 preferably draws connecting lines between the mark of the reference spindle motor 20 and other marks. In particular, when three or more marks are displayed, by specifying the reference spindle motor 20, the display can be simplified and the status of all the spindle motors 20 can be grasped relatively easily.

[0037] The reference setting unit 1344 sets the reference spindle motor 20 so that the number of other spindle motors 20 whose deviation amounts are within a predetermined range is maximized. By setting the reference spindle motor 20 in this way, it is possible to display the spindle motor 20 whose rotation speed and output value are significantly different from those of other spindle motors 20 in an easily understandable manner, so that the user can easily identify the spindle motor 20 with an abnormality.

[0038] The reference selection unit 1345 provides an interface for the user to select the spindle motor 20 to be used as the reference. By selecting the spindle motor 20 to be used as the reference at the user's discretion, the reference can be set appropriately. As an example, by setting the spindle motor 20 that has been replaced with a new one as the reference, the degree of degradation of other spindle motors 20 can be grasped more appropriately. In addition, the reference selection unit 1345 can also be used to allow the user to select a motor to be used as the reference from among the plurality of spindle motors 20 having the largest number of other ...

[0039] When the deviation exceeds the specified notification deviation, the notification unit 135 notifies that the deviation exceeds the specified notification deviation. Thus, the user can be informed of the possibility that the operation state of any of the spindle motors 20 is abnormal. Typically, the notification can be made by displaying a warning message on the display device 30, issuing an alarm, lighting a warning lamp, and the like.

[0040] The stop command unit 136 stops the spindle motor 20 when the deviation exceeds a predetermined stop deviation. This can prevent defects from occurring due to an abnormality in any of the spindle motors 20 or the abnormality from spreading to other components.

[0041] The override command unit 137 changes the rotation speed of the spindle motor 20 when the deviation exceeds the override deviation amount. Specifically, when the deviation exceeds the predetermined override deviation amount, the override command unit 137 inputs an override command to the motor control unit 12. The override command is a command that sets the speed of the spindle motor 20 to a speed different from the speed specified by the machining program, for example, overturns the speed specified by the machining program and sets it to a speed of a certain ratio.

[0042] As described above, the numerical controller 10 according to the present embodiment displays the connection line in a form that can identify the amount of deviation, and thus the user can relatively easily understand the states of all the spindle motors 20 .

[0043] The following supplementary notes are further disclosed regarding the above-mentioned embodiment and modified examples.

[0044] (Note 1)

[0045] The motor monitoring device (10) comprises: a rotation speed acquisition unit (131) for acquiring the rotation speeds of a plurality of motors (20); an output value acquisition unit (132) for acquiring the output values ​​of the plurality of motors (20); a deviation calculation unit (133) for calculating the deviation between the rotation speeds and the output values ​​of the motors (20); and a graph display unit (134) for plotting a plurality of marks representing the combination of the rotation speed and the output value for each motor (20) in a graph area in which one axis is set as the rotation speed and the other axis is set as the output value, wherein the graph display unit (134) comprises: a graph area setting unit (1341) for dividing the graph area into a plurality of load areas having different load levels based on a plurality of rated times of the motors (20) for an assumed combination of the rotation speed and the output value, and displaying the plurality of load areas in an identifiable manner; a plotting unit (1342) for plotting a plurality of marks in the graph area; and a connecting line drawing unit (1343) for drawing connecting lines connecting corresponding marks in different forms according to the deviation.

[0046] (Note 2)

[0047] Alternatively, the marking unit (1342) may mark each corresponding motor (20) in a different manner.

[0048] (Note 3)

[0049] According to the motor monitoring device of the first invention or the second invention,

[0050] The connection line drawing unit (1343) draws the connection line in different forms depending on whether the deviation amount exceeds a predetermined deviation tolerance amount.

[0051] (Note 4)

[0052] According to the motor monitoring device of the first invention or the second invention,

[0053] The connection line drawing unit (1343) draws the connection line in different forms according to the ratio between the deviation amount and a predetermined deviation tolerance amount.

[0054] (Note 5)

[0055] The motor monitoring device (10) may further include a notification unit (135) configured to make a notification when the deviation exceeds a predetermined notification deviation amount.

[0056] (Note 6)

[0057] The motor monitoring device (10) may further include a stop command unit (136) that stops the motor (20) when the deviation amount exceeds a predetermined stop deviation amount.

[0058] (Note 7)

[0059] The motor monitoring device (10) may further include an override command unit (137) that changes the rotation speed of the motor (20) when the deviation exceeds a predetermined override deviation amount.

[0060] (Note 8)

[0061] Alternatively, the connection line drawing unit (1343) may draw a connection line between a mark of a motor (20) serving as a reference and other marks.

[0062] (Note 9)

[0063] Alternatively, the graph display unit (134) further includes a reference setting unit (1344), which sets the motor (20) to be the reference so as to maximize the number of other motors (20) whose deviation amounts are within a specified range.

[0064] (Note 10)

[0065] Alternatively, the graph display unit (134) may further include a reference selection unit (1345) that allows a user to select a motor (20) to serve as a reference.

[0066] The present disclosure is described in detail above, but the present disclosure is not limited to the above-mentioned embodiments. These embodiments can be variously added, replaced, changed, partially deleted, etc. without departing from the scope of the main purpose of the present disclosure or the scope of the purpose of the present disclosure derived from the contents recorded in the claims and their equivalents.

[0067] The motor monitoring device of the present disclosure can be set up independently of the numerical control device for controlling the machine tool, and can also be used to confirm the status of motors other than the spindle motor of the machine tool. As an example, the motor monitoring device of the present disclosure can also be a device obtained by adding the functions of the motor monitoring unit of the above-mentioned embodiment to a management computer for managing one or more numerical control devices.

[0068] In the motor monitoring device according to the present disclosure, the notification unit, the stop command unit, and the override command unit may be omitted. In addition, the graph display unit of the motor monitoring device according to the present disclosure may not include the reference setting unit and the reference selection unit.

[0069] Description of Reference Numerals

[0070] 1: machine tool; 10: numerical control device (motor monitoring device); 11: program storage unit; 12: motor control unit; 13: motor monitoring unit; 131: rotation speed acquisition unit; 132: output value acquisition unit; 133: deviation calculation unit; 134: chart display unit; 1341: chart area setting unit; 1342: plotting unit; 1343: connecting line drawing unit; 1344: reference setting unit; 1345: reference selection unit; 135: notification unit; 136: stop command unit; 137: overrun command unit; 20: spindle motor; 21: rotation speed detector; 22: current detector; 30: display device; 40: input device.

Claims

1. A motor monitoring device, comprising: A rotation speed acquisition unit, which acquires the rotation speeds of the plurality of motors; an output value acquiring unit, which acquires output values ​​of the plurality of motors; a deviation calculation unit that calculates a deviation between the rotation speed and the output value of the motors; as well as a graph display unit that plots a plurality of marks representing combinations of the rotation speed and the output value for each of the motors in a graph region in which one axis is the rotation speed and the other axis is the output value, Wherein, the chart display unit has: a graph region setting unit that divides the graph region into a plurality of load regions having different load levels based on a plurality of rated times of the motor for assumed combinations of the rotation speed and the output value, and displays the plurality of load regions in an identifiable manner; a plotting unit that plots the plurality of marks in the graph area; as well as A connection line drawing unit draws connection lines connecting the corresponding marks in different forms according to the deviation amount.

2. The motor monitoring device according to claim 1, wherein: The plotting unit plots the mark in a different form for each of the corresponding motors.

3. The motor monitoring device according to claim 1 or 2, wherein: The connecting line drawing unit draws the connecting line in a different form depending on whether the deviation amount exceeds a predetermined deviation tolerance amount.

4. The motor monitoring device according to claim 1 or 2, wherein: The connecting line drawing unit draws the connecting line in different forms according to a ratio between the deviation amount and a predetermined deviation tolerance amount.

5. The motor monitoring device according to any one of claims 1 to 4, wherein: The device further includes a notification unit configured to perform notification when the deviation amount exceeds a predetermined notification deviation amount.

6. The motor monitoring device according to any one of claims 1 to 5, wherein: A stop command unit is further provided for stopping the motor when the deviation amount exceeds a predetermined stop deviation amount.

7. The motor monitoring device according to any one of claims 1 to 6, wherein: An override command unit is further provided for changing the rotation speed of the motor when the deviation amount exceeds a predetermined override deviation amount.

8. The motor monitoring device according to any one of claims 1 to 7, wherein: The connection line drawing unit draws the connection line between the mark of one of the motors serving as a reference and the other marks.

9. The motor monitoring device according to claim 8, wherein: The graph display unit further includes a reference setting unit configured to set the motor serving as the reference so that the number of the other motors having the deviation amount within a predetermined range is maximized.

10. The motor monitoring device according to claim 8 or 9, wherein: The graph display unit further includes a reference selection unit configured to allow a user to select the motor serving as the reference.

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